Most abundant coarse fish?

[arbocop]

What is the most abundant coarse fish in the UK? Or to be more accurate, which is the most abundant freshwater fish in the UK?

 

My first thought was that it would be the smallest fish like minnow or bleak, but even though they are in large numbers, they inhabit quite specific habitats. I then thought of the roach, but then pondered whether it may actually be carp because of all the commercial fisheries.

 

However, I've come to the conclusion that it could be brown trout. Think of all those rivers, streams, becks, burns, lakes, lochs and estuaries it inhabits, from Cornwall up to Orkney. All those bits of water in the flow country and the North of Scotland. Most of these remote lochs only have trout and pike, maybe sea trout, char and salmon in a few. Some have perch as well.

 

I reckon that there must be millions of trout in the UK.

 

Any thoughts?

Edited June 9, 2010 by arbocop

[Christy]

What is the most abundant coarse fish in the UK? Or to be more accurate, which is the most abundant freshwater fish in the UK?

 

My first thought was that it would be the smallest fish like minnow or bleak, but even though they are in large numbers, they inhabit quite specific habitats. I then thought of the roach, but then pondered whether it may actually be carp because of all the commercial fisheries.

 

However, I've come to the conclusion that it could be brown trout. Think of all those rivers, streams, becks, burns, lakes, lochs and estuaries it inhabits, from Cornwall up to Orkney. All those bits of water in the flow country and the North of Scotland. Most of these remote lochs only have trout and pike, maybe sea trout, char and salmon in a few. Some have perch as well.

 

I reckon that there must be millions of trout in the UK.

 

Any thoughts?

 

That you're most likely to catch. Undoubtedly Carp, and definitely in terms of weight!

[Steve Walker]

Against brown trout, I would say:

 

* In many rivers, their distribution is limited by water quality to the upper reaches, where the river is smaller

 

* They are a territorial fish, not a shoaling fish

 

* Trout require low nutrient levels to thrive, which means lower productivity, which tends to mean a lower total biomass of fish - habitat suitable for trout will not support as many fish per acre as habitat suitable for carp

 

* Where trout are artificially stocked, they tend to be stocked at lower densities than where coarse fish are artificially stocked

 

There are several ways of looking at it, though - most numerous, most total weight, most ubiquitous. If we were considering which fish is present in the greatest area of water, then I suspect the perch would be in with a shout, having almost as great a representation as brown trout in the clean, upland waters and being present all the way to the sea in the lowland rivers.

[Kevin Massey]

Minnows

[arbocop]

There are several ways of looking at it, though - most numerous, most total weight, most ubiquitous.

 

 

Solely on abundance - numbers of a species. I agree that perch are everywhere too. I still think it's brownies!

[GlennB]

Most numerous? My guess is roach, though maybe bleak. Roach go where bleak don't, but if there are bleak there's an awful lot of them.

[Dales]

I would still have thought it was the Roach, even in waters that seem packed mainly with Carp there is often a big head of Roach, it's just no one sees them in the muddy water and they don't get caught very often on the large hooks and baits. But I agree that the Perch would be in with a shout, they do seem to be everywhere, but are they in large numbers in a lot of places

[arbocop]

Most numerous? My guess is roach, though maybe bleak. Roach go where bleak don't, but if there are bleak there's an awful lot of them.

 

 

Maybe bleak, but they are only in rivers, and mainly in the south. What about all those lochs, lakes and ponds! I go with roach as a very close second, but then they're not really evident in the rivers and lochs in scotland, and there's an awful lot of water in scotland - but you could be right.

[Vagabond]

Steve Walker is right in his case against trout.

 

If its sheer numbers you want, then you would have to consider the minnow in with a shout.

 

..also, think food pyramids - many minnows are needed to support one larger predator such as perch, trout, chub, jack pike, etc etc etc.

 

Minnows teem in their thousands/millions in many rivers, from tiny streams (which make up the bulk of running water habitats) well down into the middle reaches of the rivers, and also in the larger lakes and lochs (which by their sheer acreage - even after discounting the very deep areas, must make up a huge proportion of the total still water in the UK) I don't know how far north the minnow ranges, but I have seen them as far north as Loch Clunie - so even if that is the northern limit, the minnow range still includes an awful lot of lochs.

 

You could probably lose the population of all the carp mudholes in just ONE of the big lochs, or a lake such as Windermere or Coniston, and just about achieve parity (in terms of numbers) with its minnow population.

 

....and just because minnows are not always obvious and bait-stealing doesn't mean they are not there...

[arbocop]

Steve Walker is right in his case against trout.

 

If its sheer numbers you want, then you would have to consider the minnow in with a shout.

 

..also, think food pyramids - many minnows are needed to support one larger predator such as perch, trout, chub, jack pike, etc etc etc.

 

Minnows teem in their thousands/millions in many rivers, from tiny streams (which make up the bulk of running water habitats) well down into the middle reaches of the rivers, and also in the larger lakes and lochs (which by their sheer acreage - even after discounting the very deep areas, must make up a huge proportion of the total still water in the UK) I don't know how far north the minnow ranges, but I have seen them as far north as Loch Clunie - so even if that is the northern limit, the minnow range still includes an awful lot of lochs.

 

....and just because minnows are not always obvious and bait-stealing doesn't mean they are not there...

 

 

Fair points, possibly minnows then. Mainly flowing water though, but I take your point. As regards the food pyramid though, not all trout are mature. Trout predate upon trout in many cases. I'm still sticking with brownies, but perhaps minnows are now second. Any more offers?

 

I like this thread!